The Arduino Mega 2560 R3 board is built upon an AVR ATmega2560 microcontroller running at 16MHz. The ATmega is pre-programmed with the Arduino bootloader that allows you to upload code to the ATmega2560 via USB using the open-source Arduino development environment. The ATmega2560's UART0 is connected to an ATmega16U2 USB-to-Serial converter chip, so you can connect the board to your PC via USB and download your code.

The board has 54 digital input/output pins (of which 14 can be used as PWM outputs), 16 analog inputs, 4 UARTs (hardware serial ports), a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button.

It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable, or power it with an optional AC-to-DC adapter (7V to 12V DC), or a 9V battery to get started. The Arduino Mega board is compatible with most "shields" (add-on boards) designed for the Arduino Uno, Duemilanove or Diecimila boards.

This board is R3, making it also compatible with newer Arduino shields that use additional pins. Arduino R3 adds SDA and SCL pins near the AREF pin, and two other new pins placed near the RESET pin. One is called IOREF, which allows R3 shields to adapt to the voltage provided from the board. The other new pin is not connected; it is reserved for future purposes.

Because the board features Atmel's own USB-to-Serial chip instead of an FTDI chip, there is no need for drivers under Linux or Mac (only an .inf file included with the Arduino IDE is required for Windows), and you have the ability to make the board show up as various types of devices.

About Arduino

Arduino is an open-source platform based on boards featuring an Atmel AVR microcontroller with a pre-programmed bootloader and a development environment that implements the Processing/Wiring language. Arduino can be used to develop stand-alone interactive objects or can be connected to software on your computer (e.g. Flash, Processing, MaxMSP). The open-source IDE can be downloaded for free (currently for Mac OS X, Windows, and Linux).

Expanded Functionality with Arduino Shields

The Arduino's I/O port pins are not just for wiring to a breadboard. Ready-to-use add-on peripheral boards called Arduino Shields can plug into them. In some cases, multiple shields can be stacked on top of one another.

Note: If you choose the GSM/GPRS Module for Arduino add-on board below, you also will need a compatible antenna which is not included.